Safe unmanned aircraft

ABSTRACT

An unmanned aerial vehicle (UAV) is provided including a fuselage, a pair of wings extending outwardly from the fuselage, and a deployable surface moveable from a first undeployed position during normal flight to a second deployed position when there is a system failure during flight. A method of adjusting a center of pressure of a UAV is also provided including the steps of providing a UAV with a fuselage, a pair of wings extending outwardly from the fuselage, and a deployable surface moveable from a first undeployed position during normal flight to a second deployed position when there is a system failure during flight, sensing when there is a system failure, and moving the deployable surface from the first undeployed position to the second deployed position.

An unmanned vehicle, which may also be referred to as an autonomousvehicle, is a vehicle capable of travel without a physically-presenthuman operator. An unmanned vehicle may operate in a remote-controlmode, in an autonomous mode, or in a partially autonomous mode.

When an unmanned vehicle operates in a remote-control mode, a pilot ordriver that is at a remote location can control the unmanned vehicle viacommands that are sent to the unmanned vehicle via a wireless link. Whenthe unmanned vehicle operates in autonomous mode, the unmanned vehicletypically moves based on pre-programmed navigation waypoints, dynamicautomation systems, or a combination of these. Further, some unmannedvehicles can operate in both a remote-control mode and an autonomousmode, and in some instances may do so simultaneously. For instance, aremote pilot or driver may wish to leave navigation to an autonomoussystem while manually performing another task, such as operating amechanical system for picking up objects, as an example.

Various types of unmanned vehicles exist for various differentenvironments. For instance, unmanned vehicles exist for operation in theair, on the ground, underwater, and in space. Examples includequad-copters and tail-sitter UAVs, among others. Unmanned vehicles alsoexist for hybrid operations in which multi-environment operation ispossible. Examples of hybrid unmanned vehicles include an amphibiouscraft that is capable of operation on land as well as on water or afloatplane that is capable of landing on water as well as on land. Otherexamples are also possible.

UAVs may be used to deliver a payload to, or retrieve a payload from, anindividual or business. In some cases, the UAV may fail, such as whenthere is a system failure and/or the motors stop working. In suchsituations, the UAV will fall or plummet to ground, which is notdesirable as the UAV may damage itself or ground-based objects when theUAV strikes the ground. In addition, most winged aircraft have a centerof gravity that is positioned forward from a center of pressure foraerodynamic forward flight. A resulting moment caused by the center ofpressure and the center of gravity causes the UAV to fall “nose down”when the motors stop working resulting in a high terminal velocity andincreased force resulting when the UAV strikes the ground.

As a result, it would be desirable to provide a UAV that has improvedfeatures that provides that the UAV falls more “softly” when there is asystem failure and/or the motors stop working, such that there is asofter landing when the UAV ultimately returns to the ground during sucha flight failure.

SUMMARY

The present embodiments advantageously provide a UAV with deployablesurfaces that may automatically deploy to provide a greater surface areathat is parallel to the ground when the UAV experiences a system failureand/or the motors stop working. In one example, the nose section of theUAV may include a plate that extends from a first undeployed position toa second deployed position where the plate extends outwardly from thenose section when the motors stop working. The nose plate may rotate orextend linearly forward from the nose section to provide a greatersurface area on the underside of the nose section of the UAV.

Therefore, when the nose plate is deployed, the greater surface areaprovided by the nose plate perpendicular to the downward movement of theUAV allows the UAV to return to the ground more softly than if it was ina nose dive as the UAV has a lower terminal velocity when the UAV is inthe normal forward flight position with the major lower surfaces of theUAV facing the ground. If the UAV is light enough, the UAV may fall tothe ground “like a leaf,” rather than in a nose dive.

The deployable surfaces may also take the form of boom extensions thatare moved into a forward position from the booms, either throughrotation about a pivot axis or moving forward linearly to provide agreater surface area to the bottom of the UAV. The boom extensions mayalso take the form of boom sideboards that rotate about a longitudinalpivot axis to a side of the booms, providing a greater surface area tothe underside of the booms.

The boom extensions provide the same advantages as the nose plate,allowing the UAV to stay in a normal flight position with the majorsurfaces on the bottom of the UAV facing the ground perpendicular to thedirection of descent, providing maximum drag to provide for a softer,more stable, landing on the ground

The greater surface of area created by the nose plate or boom extensionsmoves a center of pressure of the UAV towards, or in alignment with, acenter of gravity of the UAV, thereby reducing or eliminating a momentcaused by a difference between the center of pressure and center ofgravity and reducing the possibility that the UAV enters into a nosedive when the there is a system failure or the motors stop working.

In one aspect, an unmanned aerial vehicle (UAV) is provided thatincludes a fuselage, a pair of wings extending outwardly from thefuselage; and a deployable surface moveable from a first undeployedposition during normal flight to a second deployed position when thereis a system failure during flight. The deployable surface may take theform of an extendable nose plate or boom extensions on the UAV.

In another aspect, a method of adjusting a center of pressure of a UAVis provided, including the (i) providing a UAV with a fuselage, a pairof wings extending outwardly from the fuselage, and a deployable surfacemoveable from a first undeployed position during normal flight to asecond deployed position when there is a system failure during flight;(ii) sustaining a system failure; and (iii) moving the deployablesurface from the first undeployed position to the second deployedposition.

The present embodiments further provide means for moving a center ofpressure towards, or in alignment with, a center of gravity of the UAVusing deployable surfaces.

These as well as other aspects, advantages, and alternatives will becomeapparent to those of ordinary skill in the art by reading the followingdetailed description with reference where appropriate to theaccompanying drawings. Further, it should be understood that thedescription provided in this summary section and elsewhere in thisdocument is intended to illustrate the claimed subject matter by way ofexample and not by way of limitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an example unmanned aerial vehicle 100,according to an example embodiment.

FIG. 1B is a simplified illustration of an unmanned aerial vehicle,according to an example embodiment.

FIG. 1C is a simplified illustration of an unmanned aerial vehicle,according to an example embodiment.

FIG. 1D is a simplified illustration of an unmanned aerial vehicle,according to an example embodiment.

FIG. 2 is a simplified block diagram illustrating components of anunmanned aerial vehicle, according to an example embodiment

FIG. 3 is a simplified block diagram illustrating a UAV system,according to an example embodiment.

FIG. 4A is a perspective view of aerial vehicle 100 having a deployablenose plate 500 in an undeployed position, according to an exampleembodiment.

FIG. 4B is a perspective view of aerial vehicle 100 with nose plate 500rotated into a deployed position, according to an example embodiment.

FIG. 4C is a perspective view of aerial vehicle 100 shown in FIG. 4Awith nose plate 500 moved linearly into a deployed position, accordingto an example embodiment.

FIG. 5 is a perspective view of aerial vehicle 100 having boomextensions 600 rotated into a deployed position in the front of booms104, according to an example embodiment.

FIG. 6 is a perspective view of aerial vehicle 100 having boomextensions 600 moved linearly into a deployed position in front of booms104, according to an example embodiment.

FIG. 7A is a perspective view of aerial vehicle 100 having boomextension side boards 640 shown in an undeployed position, according toan example embodiment.

FIG. 7B is a perspective view of aerial vehicle 100 shown in FIG. 7Awith boom extension side boards 640 shown in a deployed position on theside of booms 104, according to an example embodiment.

FIG. 8A is a perspective view of aerial vehicle 100 with verticalstabilizers 116 extending from rear booms 137, according to an exampleembodiment.

FIG. 8B is a perspective view of aerial vehicle 100 shown in FIG. 8Awith vertical stabilizers 116 rotated, according to an exampleembodiment.

FIG. 9 is a perspective view of aerial vehicle 100 having fixed boomextensions 660, according to an example embodiment.

FIG. 10A is an illustration of a UAV 700 showing the position of thecenter of pressure 710 and the center of gravity 720 during a normalstable forward flight.

FIG. 10B is an illustration of UAV 700 with the deployable surface 500,shown in a deployed state, illustrating how the center of pressure 710has moved towards the center of gravity 720 after the surface 500 hasbeen deployed.

DETAILED DESCRIPTION

Exemplary methods and systems are described herein. It should beunderstood that the word “exemplary” is used herein to mean “serving asan example, instance, or illustration.” Any implementation or featuredescribed herein as “exemplary” or “illustrative” is not necessarily tobe construed as preferred or advantageous over other implementations orfeatures. In the figures, similar symbols typically identify similarcomponents, unless context dictates otherwise. The exampleimplementations described herein are not meant to be limiting. It willbe readily understood that the aspects of the present disclosure, asgenerally described herein, and illustrated in the figures, can bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are contemplatedherein.

I. Overview

The present embodiments advantageously provide a UAV with deployablesurfaces that may automatically deploy to provide a greater surface areathat is parallel to the ground when the UAV experiences a system failureand/or the motors stop working. The greater surface area caused by thedeployed surfaces provides maximum drag on the UAV in a direction ofdownward travel. In one example, the nose section of the UAV may includea plate that extends from a first undeployed position to a seconddeployed position where the plate extends outwardly from the nosesection when the motors stop working. The nose plate may rotate orextend linearly forward from the nose section to provide a greatersurface area on the underside of the nose section of the UAV.

Therefore, when the nose plate is deployed, the greater surface areaprovided by the nose plate perpendicular to the downward movement of theUAV allows the UAV to return to the ground more softly than if it was ina nose dive as the UAV has a lower terminal velocity when the UAV is inthe normal forward flight position with the major lower surfaces of theUAV facing the ground. If the UAV is light enough, the UAV may fall tothe ground “like a leaf,” rather than in a nose dive.

The deployable surfaces may also take the form of boom extensions thatare moved into a forward position from the boom, either through rotationabout a pivot axis or moving forward linearly to provide a greatersurface area to the bottom of the UAV. The boom extensions may also takethe form of boom sideboards that rotate about a longitudinal pivot axisto a side of the booms, providing a greater surface area to theunderside of the booms.

The boom extensions provide the same advantages as the nose plate,allowing the UAV to stay in a normal horizontal flight position with themajor surfaces on the bottom of the UAV facing the ground perpendicularto the direction of descent, providing maximum drag to provide for asofter, more stable, landing on the ground.

The greater surface of area created by the nose plate or boom extensionsmoves a center of pressure of the UAV towards, or in alignment with, acenter of gravity of the UAV, thereby reducing or eliminating a momentcaused by a difference between the center of pressure and center ofgravity and reducing the possibility that the UAV enters into a nosedive when there is a system failure and/or the motors stop working.

II. Illustrative Unmanned Vehicles

Herein, the terms “unmanned aerial vehicle” and “UAV” refer to anyautonomous or semi-autonomous vehicle that is capable of performing somefunctions without a physically present human pilot.

A UAV can take various forms. For example, a UAV may take the form of afixed-wing aircraft, a glider aircraft, a tail-sitter aircraft, a jetaircraft, a ducted fan aircraft, a lighter-than-air dirigible such as ablimp or steerable balloon, a rotorcraft such as a helicopter ormulticopter, and/or an ornithopter, among other possibilities. Further,the terms “drone,” “unmanned aerial vehicle system” (UAVS), or “unmannedaerial system” (UAS) may also be used to refer to a UAV.

FIG. 1A is an isometric view of an example UAV 100. UAV 100 includeswing 102, booms 104, and a fuselage 106. Wings 102 may be stationary andmay generate lift based on the wing shape and the UAV's forwardairspeed. For instance, the two wings 102 may have an airfoil-shapedcross section to produce an aerodynamic force on UAV 100. In someembodiments, wing 102 may carry horizontal propulsion units 108, andbooms 104 may carry vertical propulsion units 110. In operation, powerfor the propulsion units may be provided from a battery compartment 112of fuselage 106. In some embodiments, fuselage 106 also includes anavionics compartment 114, an additional battery compartment (not shown)and/or a delivery unit (not shown, e.g., a winch system) for handlingthe payload. In some embodiments, fuselage 106 is modular, and two ormore compartments (e.g., battery compartment 112, avionics compartment114, other payload and delivery compartments) are detachable from eachother and securable to each other (e.g., mechanically, magnetically, orotherwise) to contiguously form at least a portion of fuselage 106.

In some embodiments, booms 104 terminate in rudders 116 for improved yawcontrol of UAV 100. Further, wings 102 may terminate in wing tips 117for improved control of lift of the UAV.

In the illustrated configuration, UAV 100 includes a structural frame.The structural frame may be referred to as a “structural H-frame” or an“H-frame” (not shown) of the UAV. The H-frame may include, within wings102, a wing spar (not shown) and, within booms 104, boom carriers (notshown). In some embodiments the wing spar and the boom carriers may bemade of carbon fiber, hard plastic, aluminum, light metal alloys, orother materials. The wing spar and the boom carriers may be connectedwith clamps. The wing spar may include pre-drilled holes for horizontalpropulsion units 108, and the boom carriers may include pre-drilledholes for vertical propulsion units 110.

In some embodiments, fuselage 106 may be removably attached to theH-frame (e.g., attached to the wing spar by clamps, configured withgrooves, protrusions or other features to mate with correspondingH-frame features, etc.). In other embodiments, fuselage 106 similarlymay be removably attached to wings 102. The removable attachment offuselage 106 may improve quality and or modularity of UAV 100. Forexample, electrical/mechanical components and/or subsystems of fuselage106 may be tested separately from, and before being attached to, theH-frame. Similarly, printed circuit boards (PCBs) 118 may be testedseparately from, and before being attached to, the boom carriers,therefore eliminating defective parts/subassemblies prior to completingthe UAV. For example, components of fuselage 106 (e.g., avionics,battery unit, delivery units, an additional battery compartment, etc.)may be electrically tested before fuselage 106 is mounted to theH-frame. Furthermore, the motors and the electronics of PCBs 118 mayalso be electrically tested before the final assembly. Generally, theidentification of the defective parts and subassemblies early in theassembly process lowers the overall cost and lead time of the UAV.Furthermore, different types/models of fuselage 106 may be attached tothe H-frame, therefore improving the modularity of the design. Suchmodularity allows these various parts of UAV 100 to be upgraded withouta substantial overhaul to the manufacturing process.

In some embodiments, a wing shell and boom shells may be attached to theH-frame by adhesive elements (e.g., adhesive tape, double-sided adhesivetape, glue, etc.). Therefore, multiple shells may be attached to theH-frame instead of having a monolithic body sprayed onto the H-frame. Insome embodiments, the presence of the multiple shells reduces thestresses induced by the coefficient of thermal expansion of thestructural frame of the UAV. As a result, the UAV may have betterdimensional accuracy and/or improved reliability.

Moreover, in at least some embodiments, the same H-frame may be usedwith the wing shell and/or boom shells having different size and/ordesign, therefore improving the modularity and versatility of the UAVdesigns. The wing shell and/or the boom shells may be made of relativelylight polymers (e.g., closed cell foam) covered by the harder, butrelatively thin, plastic skins.

The power and/or control signals from fuselage 106 may be routed to PCBs118 through cables running through fuselage 106, wings 102, and booms104. In the illustrated embodiment, UAV 100 has four PCBs, but othernumbers of PCBs are also possible. For example, UAV 100 may include twoPCBs, one per the boom. The PCBs carry electronic components 119including, for example, power converters, controllers, memory, passivecomponents, etc. In operation, propulsion units 108 and 110 of UAV 100are electrically connected to the PCBs.

Many variations on the illustrated UAV are possible. For instance,fixed-wing UAVs may include more or fewer rotor units (vertical orhorizontal), and/or may utilize a ducted fan or multiple ducted fans forpropulsion. Further, UAVs with more wings (e.g., an “x-wing”configuration with four wings), are also possible. Although FIG. 1Aillustrates two wings 102, two booms 104, two horizontal propulsionunits 108, and six vertical propulsion units 110 per boom 104, it shouldbe appreciated that other variants of UAV 100 may be implemented withmore or less of these components. For example, UAV 100 may include fourwings 102, four booms 104, and more or less propulsion units (horizontalor vertical).

Similarly, FIG. 1B shows another example of a fixed-wing UAV 120. Thefixed-wing UAV 120 includes a fuselage 122, two wings 124 with anairfoil-shaped cross section to provide lift for the UAV 120, a verticalstabilizer 126 (or fin) to stabilize the plane's yaw (turn left orright), a horizontal stabilizer 128 (also referred to as an elevator ortailplane) to stabilize pitch (tilt up or down), landing gear 130, and apropulsion unit 132, which can include a motor, shaft, and propeller.

FIG. 1C shows an example of a UAV 140 with a propeller in a pusherconfiguration. The term “pusher” refers to the fact that a propulsionunit 142 is mounted at the back of the UAV and “pushes” the vehicleforward, in contrast to the propulsion unit being mounted at the frontof the UAV. Similar to the description provided for FIGS. 1A and 1B,FIG. 1C depicts common structures used in a pusher plane, including afuselage 144, two wings 146, vertical stabilizers 148, and thepropulsion unit 142, which can include a motor, shaft, and propeller.

FIG. 1D shows an example of a tail-sitter UAV 160. In the illustratedexample, the tail-sitter UAV 160 has fixed wings 162 to provide lift andallow the UAV 160 to glide horizontally (e.g., along the x-axis, in aposition that is approximately perpendicular to the position shown inFIG. 1D). However, the fixed wings 162 also allow the tail-sitter UAV160 to take off and land vertically on its own.

For example, at a launch site, the tail-sitter UAV 160 may be positionedvertically (as shown) with its fins 164 and/or wings 162 resting on theground and stabilizing the UAV 160 in the vertical position. Thetail-sitter UAV 160 may then take off by operating its propellers 166 togenerate an upward thrust (e.g., a thrust that is generally along they-axis). Once at a suitable altitude, the tail-sitter UAV 160 may useits flaps 168 to reorient itself in a horizontal position, such that itsfuselage 170 is closer to being aligned with the x-axis than the y-axis.Positioned horizontally, the propellers 166 may provide forward thrustso that the tail-sitter UAV 160 can fly in a similar manner as a typicalairplane.

Many variations on the illustrated fixed-wing UAVs are possible. Forinstance, fixed-wing UAVs may include more or fewer propellers, and/ormay utilize a ducted fan or multiple ducted fans for propulsion.Further, UAVs with more wings (e.g., an “x-wing” configuration with fourwings), with fewer wings, or even with no wings, are also possible.

It should be understood that references herein to an “unmanned” aerialvehicle or UAV can apply equally to autonomous and semi-autonomousaerial vehicles. In an autonomous implementation, all functionality ofthe aerial vehicle is automated; e.g., pre-programmed or controlled viareal-time computer functionality that responds to input from varioussensors and/or pre-determined information. In a semi-autonomousimplementation, some functions of an aerial vehicle may be controlled bya human operator, while other functions are carried out autonomously.Further, in some embodiments, a UAV may be configured to allow a remoteoperator to take over functions that can otherwise be controlledautonomously by the UAV. Yet further, a given type of function may becontrolled remotely at one level of abstraction and performedautonomously at another level of abstraction. For example, a remoteoperator could control high level navigation decisions for a UAV, suchas by specifying that the UAV should travel from one location to another(e.g., from a warehouse in a suburban area to a delivery address in anearby city), while the UAV's navigation system autonomously controlsmore fine-grained navigation decisions, such as the specific route totake between the two locations, specific flight controls to achieve theroute and avoid obstacles while navigating the route, and so on.

More generally, it should be understood that the example UAVs describedherein are not intended to be limiting. Example embodiments may relateto, be implemented within, or take the form of any type of unmannedaerial vehicle.

III. Illustrative UAV Components

FIG. 2 is a simplified block diagram illustrating components of a UAV200, according to an example embodiment. UAV 200 may take the form of,or be similar in form to, one of the UAVs 100, 120, 140, and 160described in reference to FIGS. 1A-1D. However, UAV 200 may also takeother forms.

UAV 200 may include various types of sensors, and may include acomputing system configured to provide the functionality describedherein. In the illustrated embodiment, the sensors of UAV 200 include aninertial measurement unit (IMU) 202, ultrasonic sensor(s) 204, and a GPS206, among other possible sensors and sensing systems.

In the illustrated embodiment, UAV 200 also includes one or moreprocessors 208. A processor 208 may be a general-purpose processor or aspecial purpose processor (e.g., digital signal processors, applicationspecific integrated circuits, etc.). The one or more processors 208 canbe configured to execute computer-readable program instructions 212 thatare stored in the data storage 210 and are executable to provide thefunctionality of a UAV described herein.

The data storage 210 may include or take the form of one or morecomputer-readable storage media that can be read or accessed by at leastone processor 208. The one or more computer-readable storage media caninclude volatile and/or non-volatile storage components, such asoptical, magnetic, organic or other memory or disc storage, which can beintegrated in whole or in part with at least one of the one or moreprocessors 208. In some embodiments, the data storage 210 can beimplemented using a single physical device (e.g., one optical, magnetic,organic or other memory or disc storage unit), while in otherembodiments, the data storage 210 can be implemented using two or morephysical devices.

As noted, the data storage 210 can include computer-readable programinstructions 212 and perhaps additional data, such as diagnostic data ofthe UAV 200. As such, the data storage 210 may include programinstructions 212 to perform or facilitate some or all of the UAVfunctionality described herein. For instance, in the illustratedembodiment, program instructions 212 include a navigation module 214 anda tether control module 216.

A. Sensors

In an illustrative embodiment, IMU 202 may include both an accelerometerand a gyroscope, which may be used together to determine an orientationof the UAV 200. In particular, the accelerometer can measure theorientation of the vehicle with respect to earth, while the gyroscopemeasures the rate of rotation around an axis. IMUs are commerciallyavailable in low-cost, low-power packages. For instance, an IMU 202 maytake the form of or include a miniaturized MicroElectroMechanical System(MEMS) or a NanoElectroMechanical System (NEMS). Other types of IMUs mayalso be utilized.

An IMU 202 may include other sensors, in addition to accelerometers andgyroscopes, which may help to better determine position and/or help toincrease autonomy of the UAV 200. Two examples of such sensors aremagnetometers and pressure sensors. In some embodiments, a UAV mayinclude a low-power, digital 3-axis magnetometer, which can be used torealize an orientation independent electronic compass for accurateheading information. However, other types of magnetometers may beutilized as well. Other examples are also possible. Further, note that aUAV could include some or all of the above-described inertia sensors asseparate components from an IMU.

UAV 200 may also include a pressure sensor or barometer, which can beused to determine the altitude of the UAV 200. Alternatively, othersensors, such as sonic altimeters or radar altimeters, can be used toprovide an indication of altitude, which may help to improve theaccuracy of and/or prevent drift of an IMU.

In a further aspect, UAV 200 may include one or more sensors that allowthe UAV to sense objects in the environment. For instance, in theillustrated embodiment, UAV 200 includes ultrasonic sensor(s) 204.Ultrasonic sensor(s) 204 can determine the distance to an object bygenerating sound waves and determining the time interval betweentransmission of the wave and receiving the corresponding echo off anobject. A typical application of an ultrasonic sensor for unmannedvehicles or IMUs is low-level altitude control and obstacle avoidance.An ultrasonic sensor can also be used for vehicles that need to hover ata certain height or need to be capable of detecting obstacles. Othersystems can be used to determine, sense the presence of, and/ordetermine the distance to nearby objects, such as a light detection andranging (LIDAR) system, laser detection and ranging (LADAR) system,and/or an infrared or forward-looking infrared (FLIR) system, amongother possibilities.

In some embodiments, UAV 200 may also include one or more imagingsystem(s). For example, one or more still and/or video cameras may beutilized by UAV 200 to capture image data from the UAV's environment. Asa specific example, charge-coupled device (CCD) cameras or complementarymetal-oxide-semiconductor (CMOS) cameras can be used with unmannedvehicles. Such imaging sensor(s) have numerous possible applications,such as obstacle avoidance, localization techniques, ground tracking formore accurate navigation (e.g., by applying optical flow techniques toimages), video feedback, and/or image recognition and processing, amongother possibilities.

UAV 200 may also include a GPS receiver 206. The GPS receiver 206 may beconfigured to provide data that is typical of well-known GPS systems,such as the GPS coordinates of the UAV 200. Such GPS data may beutilized by the UAV 200 for various functions. As such, the UAV may useits GPS receiver 206 to help navigate to the caller's location, asindicated, at least in part, by the GPS coordinates provided by theirmobile device. Other examples are also possible.

B. Navigation and Location Determination

The navigation module 214 may provide functionality that allows the UAV200 to, e.g., move about its environment and reach a desired location.To do so, the navigation module 214 may control the altitude and/ordirection of flight by controlling the mechanical features of the UAVthat affect flight (e.g., its rudder(s), elevator(s), aileron(s), and/orthe speed of its propeller(s)).

In order to navigate the UAV 200 to a target location, the navigationmodule 214 may implement various navigation techniques, such asmap-based navigation and localization-based navigation, for instance.With map-based navigation, the UAV 200 may be provided with a map of itsenvironment, which may then be used to navigate to a particular locationon the map. With localization-based navigation, the UAV 200 may becapable of navigating in an unknown environment using localization.Localization-based navigation may involve the UAV 200 building its ownmap of its environment and calculating its position within the mapand/or the position of objects in the environment. For example, as a UAV200 moves throughout its environment, the UAV 200 may continuously uselocalization to update its map of the environment. This continuousmapping process may be referred to as simultaneous localization andmapping (SLAM). Other navigation techniques may also be utilized.

In some embodiments, the navigation module 214 may navigate using atechnique that relies on waypoints. In particular, waypoints are sets ofcoordinates that identify points in physical space. For instance, anair-navigation waypoint may be defined by a certain latitude, longitude,and altitude. Accordingly, navigation module 214 may cause UAV 200 tomove from waypoint to waypoint, in order to ultimately travel to a finaldestination (e.g., a final waypoint in a sequence of waypoints).

In a further aspect, the navigation module 214 and/or other componentsand systems of the UAV 200 may be configured for “localization” to moreprecisely navigate to the scene of a target location. More specifically,it may be desirable in certain situations for a UAV to be within athreshold distance of the target location where a payload 228 is beingdelivered by a UAV (e.g., within a few feet of the target destination).To this end, a UAV may use a two-tiered approach in which it uses amore-general location-determination technique to navigate to a generalarea that is associated with the target location, and then use amore-refined location-determination technique to identify and/ornavigate to the target location within the general area.

For example, the UAV 200 may navigate to the general area of a targetdestination where a payload 228 is being delivered using waypointsand/or map-based navigation. The UAV may then switch to a mode in whichit utilizes a localization process to locate and travel to a morespecific location. For instance, if the UAV 200 is to deliver a payloadto a user's home, the UAV 200 may need to be substantially close to thetarget location in order to avoid delivery of the payload to undesiredareas (e.g., onto a roof, into a pool, onto a neighbor's property,etc.). However, a GPS signal may only get the UAV 200 so far (e.g.,within a block of the user's home). A more preciselocation-determination technique may then be used to find the specifictarget location.

Various types of location-determination techniques may be used toaccomplish localization of the target delivery location once the UAV 200has navigated to the general area of the target delivery location. Forinstance, the UAV 200 may be equipped with one or more sensory systems,such as, for example, ultrasonic sensors 204, infrared sensors (notshown), and/or other sensors, which may provide input that thenavigation module 214 utilizes to navigate autonomously orsemi-autonomously to the specific target location.

As another example, once the UAV 200 reaches the general area of thetarget delivery location (or of a moving subject such as a person ortheir mobile device), the UAV 200 may switch to a “fly-by-wire” modewhere it is controlled, at least in part, by a remote operator, who cannavigate the UAV 200 to the specific target location. To this end,sensory data from the UAV 200 may be sent to the remote operator toassist them in navigating the UAV 200 to the specific location.

As yet another example, the UAV 200 may include a module that is able tosignal to a passer-by for assistance in either reaching the specifictarget delivery location; for example, the UAV 200 may display a visualmessage requesting such assistance in a graphic display, play an audiomessage or tone through speakers to indicate the need for suchassistance, among other possibilities. Such a visual or audio messagemight indicate that assistance is needed in delivering the UAV 200 to aparticular person or a particular location, and might provideinformation to assist the passer-by in delivering the UAV 200 to theperson or location (e.g., a description or picture of the person orlocation, and/or the person or location's name), among otherpossibilities. Such a feature can be useful in a scenario in which theUAV is unable to use sensory functions or another location-determinationtechnique to reach the specific target location. However, this featureis not limited to such scenarios.

In some embodiments, once the UAV 200 arrives at the general area of atarget delivery location, the UAV 200 may utilize a beacon from a user'sremote device (e.g., the user's mobile phone) to locate the person. Sucha beacon may take various forms. As an example, consider the scenariowhere a remote device, such as the mobile phone of a person whorequested a UAV delivery, is able to send out directional signals (e.g.,via an RF signal, a light signal and/or an audio signal). In thisscenario, the UAV 200 may be configured to navigate by “sourcing” suchdirectional signals—in other words, by determining where the signal isstrongest and navigating accordingly. As another example, a mobiledevice can emit a frequency, either in the human range or outside thehuman range, and the UAV 200 can listen for that frequency and navigateaccordingly. As a related example, if the UAV 200 is listening forspoken commands, then the UAV 200 could utilize spoken statements, suchas “I'm over here!” to source the specific location of the personrequesting delivery of a payload.

In an alternative arrangement, a navigation module may be implemented ata remote computing device, which communicates wirelessly with the UAV200. The remote computing device may receive data indicating theoperational state of the UAV 200, sensor data from the UAV 200 thatallows it to assess the environmental conditions being experienced bythe UAV 200, and/or location information for the UAV 200. Provided withsuch information, the remote computing device may determine altitudinaland/or directional adjustments that should be made by the UAV 200 and/ormay determine how the UAV 200 should adjust its mechanical features(e.g., its rudder(s), elevator(s), aileron(s), and/or the speed of itspropeller(s)) in order to effectuate such movements. The remotecomputing system may then communicate such adjustments to the UAV 200 soit can move in the determined manner.

C. Communication Systems

In a further aspect, the UAV 200 includes one or more communicationsystems 218. The communications systems 218 may include one or morewireless interfaces and/or one or more wireline interfaces, which allowthe UAV 200 to communicate via one or more networks. Such wirelessinterfaces may provide for communication under one or more wirelesscommunication protocols, such as Bluetooth, WiFi (e.g., an IEEE 802.11protocol), Long-Term Evolution (LTE), WiMAX (e.g., an IEEE 802.16standard), a radio-frequency ID (RFID) protocol, near-fieldcommunication (NFC), and/or other wireless communication protocols. Suchwireline interfaces may include an Ethernet interface, a UniversalSerial Bus (USB) interface, or similar interface to communicate via awire, a twisted pair of wires, a coaxial cable, an optical link, afiber-optic link, or other physical connection to a wireline network.

In some embodiments, a UAV 200 may include communication systems 218that allow for both short-range communication and long-rangecommunication. For example, the UAV 200 may be configured forshort-range communications using Bluetooth and for long-rangecommunications under a CDMA protocol. In such an embodiment, the UAV 200may be configured to function as a “hot spot;” or in other words, as agateway or proxy between a remote support device and one or more datanetworks, such as a cellular network and/or the Internet. Configured assuch, the UAV 200 may facilitate data communications that the remotesupport device would otherwise be unable to perform by itself.

For example, the UAV 200 may provide a WiFi connection to a remotedevice, and serve as a proxy or gateway to a cellular service provider'sdata network, which the UAV might connect to under an LTE or a 3Gprotocol, for instance. The UAV 200 could also serve as a proxy orgateway to a high-altitude balloon network, a satellite network, or acombination of these networks, among others, which a remote device mightnot be able to otherwise access.

D. Power Systems

In a further aspect, the UAV 200 may include power system(s) 220. Thepower system 220 may include one or more batteries for providing powerto the UAV 200. In one example, the one or more batteries may berechargeable and each battery may be recharged via a wired connectionbetween the battery and a power supply and/or via a wireless chargingsystem, such as an inductive charging system that applies an externaltime-varying magnetic field to an internal battery.

E. Payload Delivery

The UAV 200 may employ various systems and configurations in order totransport and deliver a payload 228. In some implementations, thepayload 228 of a given UAV 200 may include or take the form of a“package” designed to transport various goods to a target deliverylocation. For example, the UAV 200 can include a compartment, in whichan item or items may be transported. Such a package may one or more fooditems, purchased goods, medical items, or any other object(s) having asize and weight suitable to be transported between two locations by theUAV. In other embodiments, a payload 228 may simply be the one or moreitems that are being delivered (e.g., without any package housing theitems).

In some embodiments, the payload 228 may be attached to the UAV andlocated substantially outside of the UAV during some or all of a flightby the UAV. For example, the package may be tethered or otherwisereleasably attached below the UAV during flight to a target location. Inan embodiment where a package carries goods below the UAV, the packagemay include various features that protect its contents from theenvironment, reduce aerodynamic drag on the system, and prevent thecontents of the package from shifting during UAV flight.

For instance, when the payload 228 takes the form of a package fortransporting items, the package may include an outer shell constructedof water-resistant cardboard, plastic, or any other lightweight andwater-resistant material. Further, in order to reduce drag, the packagemay feature smooth surfaces with a pointed front that reduces thefrontal cross-sectional area. Further, the sides of the package maytaper from a wide bottom to a narrow top, which allows the package toserve as a narrow pylon that reduces interference effects on the wing(s)of the UAV. This may move some of the frontal area and volume of thepackage away from the wing(s) of the UAV, thereby preventing thereduction of lift on the wing(s) cause by the package. Yet further, insome embodiments, the outer shell of the package may be constructed froma single sheet of material in order to reduce air gaps or extramaterial, both of which may increase drag on the system. Additionally oralternatively, the package may include a stabilizer to dampen packageflutter. This reduction in flutter may allow the package to have a lessrigid connection to the UAV and may cause the contents of the package toshift less during flight.

In order to deliver the payload, the UAV may include a winch system 221controlled by the tether control module 216 in order to lower thepayload 228 to the ground while the UAV hovers above. As shown in FIG.2, the winch system 221 may include a tether 224, and the tether 224 maybe coupled to the payload 228 by a payload coupling apparatus 226. Thetether 224 may be wound on a spool that is coupled to a motor 222 of theUAV. The motor 222 may take the form of a DC motor (e.g., a servo motor)that can be actively controlled by a speed controller. The tethercontrol module 216 can control the speed controller to cause the motor222 to rotate the spool, thereby unwinding or retracting the tether 224and lowering or raising the payload coupling apparatus 226. In practice,the speed controller may output a desired operating rate (e.g., adesired RPM) for the spool, which may correspond to the speed at whichthe tether 224 and payload 228 should be lowered towards the ground. Themotor 222 may then rotate the spool so that it maintains the desiredoperating rate.

In order to control the motor 222 via the speed controller, the tethercontrol module 216 may receive data from a speed sensor (e.g., anencoder) configured to convert a mechanical position to a representativeanalog or digital signal. In particular, the speed sensor may include arotary encoder that may provide information related to rotary position(and/or rotary movement) of a shaft of the motor or the spool coupled tothe motor, among other possibilities. Moreover, the speed sensor maytake the form of an absolute encoder and/or an incremental encoder,among others. So in an example implementation, as the motor 222 causesrotation of the spool, a rotary encoder may be used to measure thisrotation. In doing so, the rotary encoder may be used to convert arotary position to an analog or digital electronic signal used by thetether control module 216 to determine the amount of rotation of thespool from a fixed reference angle and/or to an analog or digitalelectronic signal that is representative of a new rotary position, amongother options. Other examples are also possible.

Based on the data from the speed sensor, the tether control module 216may determine a rotational speed of the motor 222 and/or the spool andresponsively control the motor 222 (e.g., by increasing or decreasing anelectrical current supplied to the motor 222) to cause the rotationalspeed of the motor 222 to match a desired speed. When adjusting themotor current, the magnitude of the current adjustment may be based on aproportional-integral-derivative (PID) calculation using the determinedand desired speeds of the motor 222. For instance, the magnitude of thecurrent adjustment may be based on a present difference, a pastdifference (based on accumulated error over time), and a futuredifference (based on current rates of change) between the determined anddesired speeds of the spool.

In some embodiments, the tether control module 216 may vary the rate atwhich the tether 224 and payload 228 are lowered to the ground. Forexample, the speed controller may change the desired operating rateaccording to a variable deployment-rate profile and/or in response toother factors in order to change the rate at which the payload 228descends toward the ground. To do so, the tether control module 216 mayadjust an amount of braking or an amount of friction that is applied tothe tether 224. For example, to vary the tether deployment rate, the UAV200 may include friction pads that can apply a variable amount ofpressure to the tether 224. As another example, the UAV 200 can includea motorized braking system that varies the rate at which the spool letsout the tether 224. Such a braking system may take the form of anelectromechanical system in which the motor 222 operates to slow therate at which the spool lets out the tether 224. Further, the motor 222may vary the amount by which it adjusts the speed (e.g., the RPM) of thespool, and thus may vary the deployment rate of the tether 224. Otherexamples are also possible.

In some embodiments, the tether control module 216 may be configured tolimit the motor current supplied to the motor 222 to a maximum value.With such a limit placed on the motor current, there may be situationswhere the motor 222 cannot operate at the desired operate specified bythe speed controller. For instance, as discussed in more detail below,there may be situations where the speed controller specifies a desiredoperating rate at which the motor 222 should retract the tether 224toward the UAV 200, but the motor current may be limited such that alarge enough downward force on the tether 224 would counteract theretracting force of the motor 222 and cause the tether 224 to unwindinstead. And as further discussed below, a limit on the motor currentmay be imposed and/or altered depending on an operational state of theUAV 200.

In some embodiments, the tether control module 216 may be configured todetermine a status of the tether 224 and/or the payload 228 based on theamount of current supplied to the motor 222. For instance, if a downwardforce is applied to the tether 224 (e.g., if the payload 228 is attachedto the tether 224 or if the tether 224 gets snagged on an object whenretracting toward the UAV 200), the tether control module 216 may needto increase the motor current in order to cause the determinedrotational speed of the motor 222 and/or spool to match the desiredspeed. Similarly, when the downward force is removed from the tether 224(e.g., upon delivery of the payload 228 or removal of a tether snag),the tether control module 216 may need to decrease the motor current inorder to cause the determined rotational speed of the motor 222 and/orspool to match the desired speed. As such, the tether control module 216may be configured to monitor the current supplied to the motor 222. Forinstance, the tether control module 216 could determine the motorcurrent based on sensor data received from a current sensor of the motoror a current sensor of the power system 220. In any case, based on thecurrent supplied to the motor 222, determine if the payload 228 isattached to the tether 224, if someone or something is pulling on thetether 224, and/or if the payload coupling apparatus 226 is pressingagainst the UAV 200 after retracting the tether 224. Other examples arepossible as well.

During delivery of the payload 228, the payload coupling apparatus 226can be configured to secure the payload 228 while being lowered from theUAV by the tether 224, and can be further configured to release thepayload 228 upon reaching ground level. The payload coupling apparatus226 can then be retracted to the UAV by reeling in the tether 224 usingthe motor 222.

In some implementations, the payload 228 may be passively released onceit is lowered to the ground. For example, a passive release mechanismmay include one or more swing arms adapted to retract into and extendfrom a housing. An extended swing arm may form a hook on which thepayload 228 may be attached. Upon lowering the release mechanism and thepayload 228 to the ground via a tether, a gravitational force as well asa downward inertial force on the release mechanism may cause the payload228 to detach from the hook allowing the release mechanism to be raisedupwards toward the UAV. The release mechanism may further include aspring mechanism that biases the swing arm to retract into the housingwhen there are no other external forces on the swing arm. For instance,a spring may exert a force on the swing arm that pushes or pulls theswing arm toward the housing such that the swing arm retracts into thehousing once the weight of the payload 228 no longer forces the swingarm to extend from the housing. Retracting the swing arm into thehousing may reduce the likelihood of the release mechanism snagging thepayload 228 or other nearby objects when raising the release mechanismtoward the UAV upon delivery of the payload 228.

Active payload release mechanisms are also possible. For example,sensors such as a barometric pressure based altimeter and/oraccelerometers may help to detect the position of the release mechanism(and the payload) relative to the ground. Data from the sensors can becommunicated back to the UAV and/or a control system over a wirelesslink and used to help in determining when the release mechanism hasreached ground level (e.g., by detecting a measurement with theaccelerometer that is characteristic of ground impact). In otherexamples, the UAV may determine that the payload has reached the groundbased on a weight sensor detecting a threshold low downward force on thetether and/or based on a threshold low measurement of power drawn by thewinch when lowering the payload.

Other systems and techniques for delivering a payload, in addition or inthe alternative to a tethered delivery system are also possible. Forexample, a UAV 200 could include an air-bag drop system or a parachutedrop system. Alternatively, a UAV 200 carrying a payload could simplyland on the ground at a delivery location. Other examples are alsopossible.

IV. Illustrative UAV Deployment Systems

UAV systems may be implemented in order to provide various UAV-relatedservices. In particular, UAVs may be provided at a number of differentlaunch sites that may be in communication with regional and/or centralcontrol systems. Such a distributed UAV system may allow UAVs to bequickly deployed to provide services across a large geographic area(e.g., that is much larger than the flight range of any single UAV). Forexample, UAVs capable of carrying payloads may be distributed at anumber of launch sites across a large geographic area (possibly eventhroughout an entire country, or even worldwide), in order to provideon-demand transport of various items to locations throughout thegeographic area. FIG. 3 is a simplified block diagram illustrating adistributed UAV system 300, according to an example embodiment.

In the illustrative UAV system 300, an access system 302 may allow forinteraction with, control of, and/or utilization of a network of UAVs304. In some embodiments, an access system 302 may be a computing systemthat allows for human-controlled dispatch of UAVs 304. As such, thecontrol system may include or otherwise provide a user interface throughwhich a user can access and/or control the UAVs 304.

In some embodiments, dispatch of the UAVs 304 may additionally oralternatively be accomplished via one or more automated processes. Forinstance, the access system 302 may dispatch one of the UAVs 304 totransport a payload to a target location, and the UAV may autonomouslynavigate to the target location by utilizing various on-board sensors,such as a GPS receiver and/or other various navigational sensors.

Further, the access system 302 may provide for remote operation of aUAV. For instance, the access system 302 may allow an operator tocontrol the flight of a UAV via its user interface. As a specificexample, an operator may use the access system 302 to dispatch a UAV 304to a target location. The UAV 304 may then autonomously navigate to thegeneral area of the target location. At this point, the operator may usethe access system 302 to take control of the UAV 304 and navigate theUAV to the target location (e.g., to a particular person to whom apayload is being transported). Other examples of remote operation of aUAV are also possible.

In an illustrative embodiment, the UAVs 304 may take various forms. Forexample, each of the UAVs 304 may be a UAV such as those illustrated inFIGS. 1A-1D. However, UAV system 300 may also utilize other types ofUAVs without departing from the scope of the invention. In someimplementations, all of the UAVs 304 may be of the same or a similarconfiguration. However, in other implementations, the UAVs 304 mayinclude a number of different types of UAVs. For instance, the UAVs 304may include a number of types of UAVs, with each type of UAV beingconfigured for a different type or types of payload deliverycapabilities.

The UAV system 300 may further include a remote device 306, which maytake various forms. Generally, the remote device 306 may be any devicethrough which a direct or indirect request to dispatch a UAV can bemade. (Note that an indirect request may involve any communication thatmay be responded to by dispatching a UAV, such as requesting a packagedelivery). In an example embodiment, the remote device 306 may be amobile phone, tablet computer, laptop computer, personal computer, orany network-connected computing device. Further, in some instances, theremote device 306 may not be a computing device. As an example, astandard telephone, which allows for communication via plain oldtelephone service (POTS), may serve as the remote device 306. Othertypes of remote devices are also possible.

Further, the remote device 306 may be configured to communicate withaccess system 302 via one or more types of communication network(s) 308.For example, the remote device 306 may communicate with the accesssystem 302 (or a human operator of the access system 302) bycommunicating over a POTS network, a cellular network, and/or a datanetwork such as the Internet. Other types of networks may also beutilized.

In some embodiments, the remote device 306 may be configured to allow auser to request delivery of one or more items to a desired location. Forexample, a user could request UAV delivery of a package to their homevia their mobile phone, tablet, or laptop. As another example, a usercould request dynamic delivery to wherever they are located at the timeof delivery. To provide such dynamic delivery, the UAV system 300 mayreceive location information (e.g., GPS coordinates, etc.) from theuser's mobile phone, or any other device on the user's person, such thata UAV can navigate to the user's location (as indicated by their mobilephone).

In an illustrative arrangement, the central dispatch system 310 may be aserver or group of servers, which is configured to receive dispatchmessages requests and/or dispatch instructions from the access system302. Such dispatch messages may request or instruct the central dispatchsystem 310 to coordinate the deployment of UAVs to various targetlocations. The central dispatch system 310 may be further configured toroute such requests or instructions to one or more local dispatchsystems 312. To provide such functionality, the central dispatch system310 may communicate with the access system 302 via a data network, suchas the Internet or a private network that is established forcommunications between access systems and automated dispatch systems.

In the illustrated configuration, the central dispatch system 310 may beconfigured to coordinate the dispatch of UAVs 304 from a number ofdifferent local dispatch systems 312. As such, the central dispatchsystem 310 may keep track of which UAVs 304 are located at which localdispatch systems 312, which UAVs 304 are currently available fordeployment, and/or which services or operations each of the UAVs 304 isconfigured for (in the event that a UAV fleet includes multiple types ofUAVs configured for different services and/or operations). Additionallyor alternatively, each local dispatch system 312 may be configured totrack which of its associated UAVs 304 are currently available fordeployment and/or are currently in the midst of item transport.

In some cases, when the central dispatch system 310 receives a requestfor UAV-related service (e.g., transport of an item) from the accesssystem 302, the central dispatch system 310 may select a specific UAV304 to dispatch. The central dispatch system 310 may accordinglyinstruct the local dispatch system 312 that is associated with theselected UAV to dispatch the selected UAV. The local dispatch system 312may then operate its associated deployment system 314 to launch theselected UAV. In other cases, the central dispatch system 310 mayforward a request for a UAV-related service to a local dispatch system312 that is near the location where the support is requested and leavethe selection of a particular UAV 304 to the local dispatch system 312.

In an example configuration, the local dispatch system 312 may beimplemented as a computing system at the same location as the deploymentsystem(s) 314 that it controls. For example, the local dispatch system312 may be implemented by a computing system installed at a building,such as a warehouse, where the deployment system(s) 314 and UAV(s) 304that are associated with the particular local dispatch system 312 arealso located. In other embodiments, the local dispatch system 312 may beimplemented at a location that is remote to its associated deploymentsystem(s) 314 and UAV(s) 304.

Numerous variations on and alternatives to the illustrated configurationof the UAV system 300 are possible. For example, in some embodiments, auser of the remote device 306 could request delivery of a packagedirectly from the central dispatch system 310. To do so, an applicationmay be implemented on the remote device 306 that allows the user toprovide information regarding a requested delivery, and generate andsend a data message to request that the UAV system 300 provide thedelivery. In such an embodiment, the central dispatch system 310 mayinclude automated functionality to handle requests that are generated bysuch an application, evaluate such requests, and, if appropriate,coordinate with an appropriate local dispatch system 312 to deploy aUAV.

Further, some or all of the functionality that is attributed herein tothe central dispatch system 310, the local dispatch system(s) 312, theaccess system 302, and/or the deployment system(s) 314 may be combinedin a single system, implemented in a more complex system, and/orredistributed among the central dispatch system 310, the local dispatchsystem(s) 312, the access system 302, and/or the deployment system(s)314 in various ways.

Yet further, while each local dispatch system 312 is shown as having twoassociated deployment systems 314, a given local dispatch system 312 mayalternatively have more or fewer associated deployment systems 314.Similarly, while the central dispatch system 310 is shown as being incommunication with two local dispatch systems 312, the central dispatchsystem 310 may alternatively be in communication with more or fewerlocal dispatch systems 312.

In a further aspect, the deployment systems 314 may take various forms.In general, the deployment systems 314 may take the form of or includesystems for physically launching one or more of the UAVs 304. Suchlaunch systems may include features that provide for an automated UAVlaunch and/or features that allow for a human-assisted UAV launch.Further, the deployment systems 314 may each be configured to launch oneparticular UAV 304, or to launch multiple UAVs 304.

The deployment systems 314 may further be configured to provideadditional functions, including for example, diagnostic-relatedfunctions such as verifying system functionality of the UAV, verifyingfunctionality of devices that are housed within a UAV (e.g., a payloaddelivery apparatus), and/or maintaining devices or other items that arehoused in the UAV (e.g., by monitoring a status of a payload such as itstemperature, weight, etc.).

In some embodiments, the deployment systems 314 and their correspondingUAVs 304 (and possibly associated local dispatch systems 312) may bestrategically distributed throughout an area such as a city. Forexample, the deployment systems 314 may be strategically distributedsuch that each deployment system 314 is proximate to one or more payloadpickup locations (e.g., near a restaurant, store, or warehouse).However, the deployment systems 314 (and possibly the local dispatchsystems 312) may be distributed in other ways, depending upon theparticular implementation. As an additional example, kiosks that allowusers to transport packages via UAVs may be installed in variouslocations. Such kiosks may include UAV launch systems, and may allow auser to provide their package for loading onto a UAV and pay for UAVshipping services, among other possibilities. Other examples are alsopossible.

In a further aspect, the UAV system 300 may include or have access to auser-account database 316. The user-account database 316 may includedata for a number of user accounts, and which are each associated withone or more person. For a given user account, the user-account database316 may include data related to or useful in providing UAV-relatedservices. Typically, the user data associated with each user account isoptionally provided by an associated user and/or is collected with theassociated user's permission.

Further, in some embodiments, a person may be required to register for auser account with the UAV system 300, if they wish to be provided withUAV-related services by the UAVs 304 from UAV system 300. As such, theuser-account database 316 may include authorization information for agiven user account (e.g., a user name and password), and/or otherinformation that may be used to authorize access to a user account.

In some embodiments, a person may associate one or more of their deviceswith their user account, such that they can access the services of UAVsystem 300. For example, when a person uses an associated mobile phone,e.g., to place a call to an operator of the access system 302 or send amessage requesting a UAV-related service to a dispatch system, the phonemay be identified via a unique device identification number, and thecall or message may then be attributed to the associated user account.Other examples are also possible.

V. Example Deployable Surfaces on a UAV

FIG. 4A is a perspective view of aerial vehicle 100 having a deployablenose plate 500 in an undeployed position, according to an exampleembodiment. In FIG. 2A, nose plate 500 is shown positioned on the top ofnose section 115 of UAV 100. When UAV experiences a system failureand/or the motors stop working, the UAV will eventually fall to theground, where it may strike an earth-based object. In most wingedaircraft, the center of pressure of the UAV is behind the center ofgravity of the UAV, resulting in a moment caused between the center ofpressure and the center of gravity to cause the UAV to enter into a nosedive and strike the earth at a high rate of speed. Therefore, it isdesirable to slow the descent of the UAV by deploying additionalsurfaces at the front of the UAV (or reducing the surface area in theback) to move the center of pressure forward towards, or in alignmentwith, the center of gravity of the UAV.

FIG. 4B is a perspective view of aerial vehicle 100 with nose plate 500rotated into a deployed position, according to an example embodiment. InFIG. 4B, the nose plate 500 is shown positioned on a bottom of nosesection 115, although the nose plate 500 could also be positioned on thetop nose section 115 as shown in FIG. 4A, or somewhere in between thetop and bottom of nose section 115. The greater surface area at thefront of the UAV achieved by deployment of nose plate 500 moves thecenter of pressure forward, or in alignment with, the center of gravityof the UAV, causing the UAV to remain in a forward flight or hoverorientation, with a large surface area providing maximum drag on the UAVto slow the descent of the UAV towards the ground.

When the motors stop working, the nose plate may be automaticallydeployed and rotated into the deployed position shown in FIG. 4B. Forexample, the nose plate 500 may be spring loaded, such that when asystem failure is sensed or when electrical power is lost, or when it issensed that the motors stop working, a latch may be moved and the springloaded nose plate 500 may be spring-driven to rotate into position aboutpivot point 502. Various other means of moving the nose plate 500 intothe deployed position may also be used, including rotary actuators andthe like. In addition, the deployable surfaces may also be passivelydeployed. For example, a spring loaded pin could be held in a lockedposition via electrical power (e.g., a solenoid) from the propulsionsystem. If propulsion power is lost, the power to the solenoid is losttoo, and the pin releases the deployable surface into a deployedposition.

FIG. 4C is a perspective view of aerial vehicle 100 shown in FIG. 4Awith nose plate 500 moved linearly into a deployed position, accordingto an example embodiment. In FIG. 4C, nose plate 500 is moved forward ina linear manner to move into the deployed position shown. Linearmovement of nose plate 500 may be achieved using a linear actuator, acylinder, or spring driven, among others ways of deploying the noseplate 500 forward in a linear manner. Deployment may be guided by slot506 on nose section 115. Nose plate 500 shown deployed in FIG. 4Coperates in the same manner as nose plate 500 shown in FIG. 4B, but isdeployed differently.

FIG. 5 is a perspective view of aerial vehicle 100 having boomextensions 600 rotated into a deployed position in the front of booms104, according to an example embodiment. In FIG. 5, the boom extensionsare shown rotating into the deployed position about pivot axis 602. Aswith nose plate 500 described above, the greater surface area at thefront of the UAV achieved by deployment of boom extensions 600 moves thecenter of pressure forward, or in alignment with, the center of gravityof the UAV, causing the UAV to remain in a forward flight or hoverorientation, with a large surface area providing maximum drag on the UAVto slow the descent of the UAV towards the ground.

When the motors stop working, the boom extensions 600 may beautomatically deployed and rotated into the deployed position shown inFIG. 5. For example, the boom extensions 600 may be spring loaded, suchthat when a system failure is sensed, or when it is sensed that themotors stop working, a latch may be moved and the spring loaded boomextensions may be spring-driven to rotate into a deployed position aboutpivot axis 602. Various other means of moving the boom extensions intothe deployed position may also be used, including rotary actuators andthe like.

FIG. 6 is a perspective view of aerial vehicle 100 having boomextensions 600 moved linearly into a deployed position in front of booms104, according to an example embodiment. In FIG. 6, boom extensions 600are moved forward in a linear manner to move into the deployed positionshown. Linear movement of boom extensions 600 may be achieved using alinear actuator, a cylinder, or be spring-driven, among others ways ofdeploying the boom extensions 600 in a linear manner. Boom extensions600 shown deployed in FIG. 6 operate in the same manner as boomextensions 600 shown in FIG. 5, but are deployed differently.

FIG. 7A is a perspective view of aerial vehicle 100 having boomextension side boards 640 shown in an undeployed position, according toan example embodiment. FIG. 7B is a perspective view of aerial vehicle100 shown in FIG. 7A with boom extension side boards 640 shown in adeployed position on the side of booms 104, according to an exampleembodiment. In FIG. 7B, the boom extension side boards 640 are shownrotated into the deployed position along the side of booms 104. As withnose plate 500 and boom extensions 600 described above, the greatersurface area at the front of the UAV achieved by deployment of boomextension side boards 640 moves the center of pressure forward, or inalignment with, the center of gravity of the UAV, causing the UAV toremain in a forward flight or hover orientation, with a large surfacearea providing maximum drag on the UAV to slow the descent of the UAVtowards the ground.

When the motors stop working, the boom extension side boards 640 may beautomatically deployed and rotated into the deployed position shown inFIG. 7B. For example, the boom extension side boards 640 may be springloaded, such that when a system failure is sensed, or when it is sensedthat the motors stop working, a latch may be moved and the spring loadedboom extension side boards 640 may be spring-driven to rotate into adeployed position next to booms 104. Various other means of moving theboom extension sideboards into the deployed position may also be used,including rotary actuators and the like.

Boom extensions 600 and boom extension side boards 640 are analternative to nose plate 500 for moving the center of pressure towards,or in alignment with, the center of gravity of UAV 100. It will beappreciated that the description of nose plate 500, boom extensions 600,and boom extension sideboards 640 have been illustrated on UAV 100.However, they may also be used on any other type of UAV, including thoseillustrated in FIGS. 1B-1D, as well as any other type of UAV.

Nose plate 500, boom extensions 600, and boom extension sideboards 640may be made of a lightweight material such as styrofoam, plastic, wood,or composite material, fabric, or even lightweight steel such asaluminum which may in turn be strengthened with carbon, wood, plastic,or composite material, or even lightweight metals such as aluminum. Inaddition, nose plate 500, boom extensions 600, and boom extensionsideboards 640 are shown with particular configurations; however, theymay also have any variety of configurations and geometries, such thatany type of geometry or configuration may be used as a deployablesurface to provide the desired increased surface area upon deployment.

FIG. 8A is a perspective view of aerial vehicle 100 with verticalstabilizers 116 extending from rear booms 137, according to an exampleembodiment. FIG. 8B is a perspective view of aerial vehicle 100 shown inFIG. 8A with vertical stabilizers 116 having been rotated, according toan example embodiment. When the UAV experiences a system failure and/orthe motors stop working, the vertical stabilizers 116 may be rotated,from 0 to 90 degrees (or angles in between) to have a major surface ofthe vertical stabilizers facing in the direction of flight to reducelift and move the center of pressure of the UAV towards, or in alignmentwith, the center of gravity of the UAV, thereby serving the same purposeas deploying deployable surfaces 500, 600, and 640 described above.

FIG. 9 is a perspective view of aerial vehicle 100 having fixed boomextensions 660, according to an example embodiment. Fixed boomextensions serve to increase the downward facing surface area of booms104, thereby moving the center of pressure closer to the center ofgravity of UAV 100 in the case of uncontrolled, powerless flight. Thus,fixed boom extensions 660 are deployed at all times and the UAV does notneed to sense when there is system failure and/or the motors stopworking.

FIG. 10A is an illustration of a UAV 700 showing the position of thecenter of pressure 710 and the center of gravity 720 during a normalstable forward flight. FIG. 10B is an illustration of UAV 700 with thedeployable surface 500, such as the nose plate, boom extensions, or boomextension sideboards shown in a deployed state, illustrating how thecenter of pressure 710 has moved towards the center of gravity 720 afterthe surface 500 has been deployed.

It should be noted that a parachute could be used to slow the descent ofthe UAV when there is a system failure and/or the motors stop working.However, a parachute runs the risk of being fouled in the motors orfailing to deploy properly. Therefore, the deployable surfaces arebetter suited to provide for a soft landing in the event of a systemfailure and/or the motors stop working.

VII. Conclusion

The particular arrangements shown in the Figures should not be viewed aslimiting. It should be understood that other implementations may includemore or less of each element shown in a given Figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anexemplary implementation may include elements that are not illustratedin the Figures.

Additionally, while various aspects and implementations have beendisclosed herein, other aspects and implementations will be apparent tothose skilled in the art. The various aspects and implementationsdisclosed herein are for purposes of illustration and are not intendedto be limiting, with the true scope and spirit being indicated by thefollowing claims. Other implementations may be utilized, and otherchanges may be made, without departing from the spirit or scope of thesubject matter presented herein. It will be readily understood that theaspects of the present disclosure, as generally described herein, andillustrated in the figures, can be arranged, substituted, combined,separated, and designed in a wide variety of different configurations,all of which are contemplated herein.

What is claimed is:
 1. An unmanned aerial vehicle (UAV) comprising: afuselage; a pair of wings extending outwardly from the fuselage; and adeployable surface moveable from a first undeployed position duringnormal flight to a second deployed position when there is a systemfailure during flight; wherein the fuselage includes a nose section andthe deployable surface is a nose plate that extends forwardly from thenose section of the UAV when the nose plate is in the second deployedposition.
 2. The UAV of claim 1, wherein the nose plate is deployable byrotating about a pivot point in the nose section.
 3. The UAV of claim 1,wherein the nose plate is deployable by moving forward linearly from thenose section.
 4. An unmanned aerial vehicle (UAV) comprising: afuselage; a pair of wings extending outwardly from the fuselage; and adeployable surface moveable from a first undeployed position duringnormal flight to a second deployed position when there is a systemfailure during flight; wherein the UAV includes first and second boomsthat extend forwardly in a direction parallel to a nose section of theUAV; and wherein the deployable surface comprises a first boom extensionon the first boom and a second boom extension on the second boom.
 5. TheUAV of claim 4, wherein the first boom extension is deployable byrotating about a pivot axis on the first boom into the second deployedposition extending forwardly from the first boom; and wherein the secondboom extension is deployable by rotating about a pivot axis on thesecond boom into the second deployed position extending forwardly fromthe second boom.
 6. The UAV of claim 4, wherein the first boom extensionis deployable by moving forward linearly from the first boom into thesecond deployed position extending forwardly from the first boom; andwherein the second boom extension is deployable by moving forwardlinearly from the second boom into the second deployed positionextending forwardly from the second boom.
 7. The UAV of claim 4, whereinthe first boom extension is deployable by rotating about a longitudinalpivot axis on the first boom into the second deployed position extendingto a side of the first boom; and wherein the second boom extension isdeployable by rotating about a longitudinal pivot axis on the secondboom into the second deployed position extending to a side of the secondboom.
 8. The UAV of claim 1, wherein deployment of the deployablesurfaces moves a center of pressure of the UAV towards, or in alignmentwith, a center of gravity of the UAV.
 9. The UAV of claim 4, wherein thefirst boom also extends rearwardly from the pair of wings and thedeployable surface comprises a vertical stabilizer that extends from thefirst boom; and wherein the second boom also extends rearwardly from thepair of wings and the deployable surface comprises a vertical stabilizerthat extends from the second boom.
 10. The UAV of claim 9, wherein thevertical stabilizer on the first boom is rotatable about a pivot axis onthe first boom to the second deployed position with a major surface ofthe vertical stabilizer positioned facing a direction of forward travelof the UAV; and wherein the vertical stabilizer on the second boom isrotatable about a pivot axis on the second boom to the second deployedposition with a major surface of the vertical stabilizer positionedfacing a direction of forward travel of the UAV.
 11. A method ofadjusting a center of pressure of a UAV comprising the steps of:providing a UAV with a fuselage, a pair of wings extending outwardlyfrom the fuselage, and a deployable surface moveable from a firstundeployed position during normal flight to a second deployed positionwhen there is a system failure during flight; sustaining a systemfailure; moving the deployable surface from the first undeployedposition to the second deployed position; wherein the fuselage includesa nose section and the deployable surface comprises a nose plate thatextends forwardly from the nose section of the UAV when the nose plateis in the second deployed position.
 12. The method of claim 11, whereinmoving the nose plate to the second deployed position comprises rotatingthe nose plate about a pivot point in the nose section.
 13. The methodof claim 11, wherein moving the nose plate to the second deployedposition comprises moving the nose plate forward linearly from the nosesection.
 14. A method of adjusting a center of pressure of a UAVcomprising the steps of: providing a UAV with a fuselage, a pair ofwings extending outwardly from the fuselage, and a deployable surfacemoveable from a first undeployed position during normal flight to asecond deployed position when there is a system failure during flight;sustaining a system failure; moving the deployable surface from thefirst undeployed position to the second deployed position; wherein theUAV includes first and second booms that extend forwardly in a directionparallel to the nose section; and wherein the deployable surfacecomprises a first boom extension on the first boom and a second boomextension on the second boom.
 15. The method of claim 14, wherein movingthe first boom extension to the second deployed position comprisesrotating the first boom extension about a pivot axis on the first boomto a position extending forwardly from the first boom; and whereinmoving the second boom extension to the second deployed positioncomprises rotating the second boom extension about a pivot axis on thesecond boom to a position extending forwardly from the second boom. 16.The method of claim 14, wherein moving the first boom extension to thesecond deployed position comprises moving the first boom extensionforward linearly from the first boom into a position extending forwardlyfrom the first boom; and wherein moving the second boom extension to thesecond deployed position comprises moving the second boom extensionforward linearly from the second boom into a position extendingforwardly from the second boom.
 17. The method of claim 14, whereinmoving the first boom extension to the second deployed positioncomprises rotating the first boom extension about a pivot axis on thefirst boom into a position extending to a side of the first boom; andwherein moving the second boom extension to the second deployed positioncomprises rotating the second boom extension about a pivot axis on thesecond boom into a position extending to a side of the second boom. 18.A method of adjusting a center of pressure of a UAV comprising the stepsof: providing a UAV with a fuselage, a pair of wings extending outwardlyfrom the fuselage, and a deployable surface moveable from a firstundeployed position during normal flight to a second deployed positionwhen there is a system failure during flight; sustaining a systemfailure; moving the deployable surface from the first undeployedposition to the second deployed position; wherein deployment of thedeployable surfaces moves a center of pressure of the UAV towards or inalignment with a center of gravity of the UAV.